Hydraulic press and control means



March 8, 1960 R. SMILGES 2,927,558

HYDRAULIC PRESS AND CONTROL MEANS Filed Jan. 16, 1956 4 Sheets-Sheet 122- H a!!! v ni lfg l I 35 2o 32 "-1 32 g I 24 23 i z i a 26 I 5 sINVENTOR. ROBERT SM/LGES AGENT March 8, 1960 R. SMILGES 2,927,558

HYDRAULIC PRESS AND CONTROL MEANS Filed Jan. 16, 1956 4 Sheets-Sheet 2INVENTOR. ROBERT SM/LGES AGENT March 8, 1960 R. SMILGES 2,927,558

HYDRAULIC PRESS AND CONTROL MEANS Filed Jan. 16, 1956 4 Sheets-Sheet 3v6 q 155 u! A? LT QED as. 51 A 6| 4 k v" QQ V 65 56 I 62 4 $4 (Z vc "Ig; "g 7 J 22 72/% 4? as 36 37 69 52 A 564 INVENTOR.

ROBERT SM/LGES AGENT March 8, 1960 R. SMILGES 2,927,558

HYDRAULIC PRESS AND CONTROL- MEANS Filed Jan; 16, 1956 4 Sheets-Sheet 4IN V EN TOR. ROBERT SM/LGES AGENT HYDRAULIC PRESS AND CONTROL NIEANSsignmenis, to American Brake Shoe Company, New York, N.Y., a corporationof Delaware Application January 16, 1956, Serial No. 559,438 4 Claims."(CL 121 -1150) This invention relates to hydraulic apparatuses and itmay be applied with facility and advantages to hydraulic apparatuses inthe nature of presses.

An object of the invention is to provide improved hydraulic apparatus ofthe type hereinafter described.

Another object of the invention is to provide improved structure whichwhen applied to a hydraulic press, for example, imparts improved modesof operation thereto.

Another object of the invention is to provide improved and simplifiedapparatus for use, for example, in a hydraulic press which will causethe ram thereof to have high traverse speeds with maximum of expendedpressing energy and in which a low horsepower motor may be employed asthe prime mover.

Another object of the invention is to provide improved apparatus whichimparts an improved mode of operation to the ram of a hydraulic press,for example, and which is fully automatic in controlling theoper'ationof the press ram during each stroke or cycle of the latter once thestroke or cycle is initiated.

Another object of the invention is to provide improved apparatus in ahydraulic press, for example, whereby'the press ram is caused to descendat a rapid rate until it engages work on the press bed and then todescend at a slower or working rate while increasing its workingpressure to a predetermined limit and when such pressure is reached toreverse its direction of travel andtravel at a high rate of speed to itsstarting position. I

Another object of the invention is to provide improved apparatus as setforth in the foregoing object wherein the press ram may be caused todwell against the work alter said predetermined ram pressure has beenreached and in which, after said dwell perior is completed the ramreturns to its starting position at a high rate of speed.

Another object of the invention is to provide an improved hydraulicapparatus for operating the ram of a press, for example, wherein the ram"is operated by two separate volumes of hydraulic liquid derived fromtwo sources and which volumes of liquid are first merged and directed tothe ram motor to cause the ram to travel toward the press bed at a highrate of speed, then to separate to cause one of said volumes of liquidto be directed to said ram motor to do the pressing work, and then tore-merge and be re-direc'ted to the ram motor to cause it to return theram to its starting position at a high rate of speed.

Another object of the invention is toprovide improved apparatus as setforth in the foregoing object and wherein hydraulic fluid displaced bythe ram motor when the latter is operating to move the ram at a highspeed is added to the hydraulic liquid being supplied to said motor toincrease speed of operation of the latter.

Another object of the invention is to provide improved valve structurefor the purposes set forth in the foregoing objects which includes aspool whichis moved from one "position to another by difierent pressurescreated at its opposite ends by hydraulic liquidfloWing through'it-andSidtgg P Robert Smilges, Columbus, Ghio, assignor, by mesne as-2,927,558 a Patented Mar- 9 in which there is improved means for causing's'aidldiiferent pressures.

Still another object of the invention is to provide-inrproved orificemeans for causing liquid flowing M ethrough to create differentpressures at opposite SldS thereof which includes a pair of orificemeans of different sizes and a valve means between them responsive tothe pressure of fluid applied to the first orifice means to by. pass thesecond and smaller orifice means. 7

Further objects and advantages of the present inven- 'tion will beapparent from the following description, reference being had to theaccompanying drawings where in a preferred form of embodiment of theinvention ifs clearly shown.

In the accompanying drawings: w I

Fig. 1 is a side view of a hydraulic press including the features of theinvention, the "view showing the press frame in section, which sectionis taken on line 1-51 of Fig. 2, looking in the direction of the arrows;

Fig. 2 is a front view of the hydraulic press seen in Fig. l with theframe broken away to the plane indicated structure of the hydraulicapparatus or power hnit'ofthe press seen in Figs. 1, 2 and 3 andillustratingjits novel features and operation. The hydraulic 'pressshown in Figs. 1 through 3of t lie drawings has a frame 20 of the opengap or C type which may be formed as by casting or by fabrication fromplates which are cut and shaped and then welded into an inte'gral unit.The frame 20 is hollow for the purposeof receiving and housing thehydraulic apparatus or power unit 21 and the electric motor 22 of thepress andji't includes a bed 23, an upright open backed portion 2 1 anda head portion 25 which extends from the top of the up right backportion 24 forwardly over the bed 23. The bottom, part of the uprightportion 24 forms a tank or reservoir 26 for storing hydraulic liquid,preferably oil,

cludes a body, casing or housing formed of twosepara'te housings or"casings, namely, a body, casing or housing 27 for a pump 28 and a body,casing or housing .29 for control mechanism 30 and a hydraulicallyoperated 'ram motor 31. v

The power unit 21 'will'be des'cribedin 'detaililiere inafter, but it ispointed out here that it includesapiston shaft which forms the ram 32 ofthe press and that 'itgis so mounted in the head portion 25 of frame '20that the ram 32 thereof projects downwardly through the bottom wall ofthe head portion 25 and extends toward the center of the bed 23.Hydraulic liquid is supplied toand exhause'd from the power unit 21 byconduits 33 andd l, respectively, which extend into the tank orreservoir 26. The electric motor 22 is mounted in the upper portion ofthe upright frame portion 24 above the tank 'or reservoir 26 by brackets35 and it drives the pump "'28 through sheaves and a belt 36.

The hydraulic apparatus or power unit 21 of the press is showndiagrammatically in Figs. 4, '5 and 6.' "This apparatus includes thehydraulically operated press ram 32 which, as shown, is formedby-"thepiston rod of tlie reciprocatory hydraulic ram operating moto'1" 31.-Mbltbt 31 includes a cylinder 37- and a'piston 38. The hydraulicapparatus or power unit '21 also includes-the 'et imbl shown, and agasket 40.

here 44 of cap 39.

contained within the body, casing or housing 29 which is formed by abody or casting 38' and a cap 39 secured together in fluid tightrelation by bolts or screws, not

The body 38 includes. a central bore in which a sleeve 41 is pressedaxially and clamped against a shoulder 42 in body 38' by a shoulder 43surrounding the mouth of a stepped bore 44 in cap 39. Sleeve 41 includesa plurality of external channels or grooves 45, 46, 47, 48 and 49separated by lands which engage the walls of the bore in body 38'whereby the channels 45 through 49 form passages through which bydraulic fluid may pass circumferentially around the sleeve 41. Each ofthe channels or grooves 45 through 49 is connected to the interior ofthe sleeve 41 through ports and these ports are controlled by lands andgrooves on a hollow valve piston or spool 50 which is slidable axiallywithin the sleeve 41.

Spool 50 includes an internal wall or partition which forms an orifice51 and a valve seat against which a poppet 52 having a central orifice53 seats. Poppet 52 is preferably, but not necessarily, made of nylonand it is urged by a spring 54 contained within the lower portion of thespool 50 to seat against the partition as above described. This spring54 acts through the poppet 52 to urge the spool upwardly to the positionshown in Fig. 4 of the drawings where the upper end of spool 50 abuts ashoulder on an unloading piston 55 which is slidably positioned in theupper end of the bore in sleeve 41.

and slot 57 will be made apparent hereinafter. Unloading piston 55 isalso provided with an annular lip 59 adapted to abut the upper end ofsleeve 41 to limit its inward movement into the sleeve 41 and it isurged downwardly to the position shown in Fig. 4 of the drawings by acompression spring 60 contained within the The body 38' also houses avalve 61 which is normally open and is urged to a closed position by a,solenoid, for example, indicated diagrammatically at 62.

In Fig. 4 of the drawings, the parts of the above described structureare shown in the positions which they occupy when the ram 32 is held inits up position. Before describing the operation of the apparatus, itshould be stated that the pump 28 has two outlet or output ports whichare connected respectively to conduits or lines 63 and 64 formed in thebody 38' and that the volume of fluid delivered to the lines 63 and 64are preferably, but

not necessarily, different. In one embodiment of the invent on, theoutput volume of liquid to line 63 is approxnnately one gallon perminute and the output volume of liquid to line 64 is approximately twogallons per minute. While pump 28 is herein shown and described as oneunit having dual outlets, it is to be understood that two separate pumpsmay be employed if desired.

shown in Fig. 4, hydraulic liquid flows from the reservoir or tank 26through the conduit 33 to the pump 28 where it is divided as aforesaidand flows to lines 63 From groove 47 liquid flows through a conduit,line or pipe 68 to conduit, line or pipe 64 where it combines or mergeswith liquid discharged from the high volume output port of pump 28.Because pressure of the liquid will pass through the partition in valvespool 50, the spring 54 will maintain the valve spool 50 in the positionshown in Fig. 4 of the drawings until the valve 61 is closed.

The liquid flowing from conduit 68, as previously mentioned, merges ormixes with the liquid flowing in conduit 64 and thus, at this time, thetotal or combined output volumes of pump 28 is supplied through conduit64 to the bottom of cylinder 37 to elevate the piston 38 and ram 30.When piston 38 is in its uppermost position, liquid entering thecylinder 37 from conduit 64 is discharged from the cylinder 37 through aconduit 69 which leads to groove 49 in sleeve 41. From groove 49, thisliquid flows through a groove or channel 70 in piston 50 to channel orgroove 48 in sleeve 50 and through drain or exhaust line 34 to reservoiror tank 26.

When it is desired to start the ram 32 to descend the press bed thesolenoid 62 of valve 61 is energized to cause valve 61 to close. Withreference to Fig. 4, when valve 61 closes, hydraulic liquid flowing inconduit 63 passes through groove 45 in sleeve 41 and from this groove tothe interior of the upper end of valve spool 50 and also to valve 61where its flow is blocked. The pressure of the fluid flowing from groove45 to the interior of valve spool 50, however, will increase and forcethe fluid to flow through the orifice 51 in spool 50 and the orifice 53in poppet 52 to the interior of the lower portion of spool 50. From thebottom of spool 50, liquid flows through conduit 71 through a checkvalve 76, conduit 66, groove 46, groove 67 in spool 50 to groove 47, andconduit 68 to conduit 64. The liquid flowing through orifices 51 and 53,of course, creates a pressure differential between the upper and lowerends of the valve spool 50 and the spool 50 is thereby caused tocompress the spring 54 and move spool 50 downwardly to the positionshown in Fig. 5 of the drawings. This action or movement of the spool 50occurs very quickly when liquid flows through the orifices 51 and 53.After spool 50 moves downwardly, liquid flows from the bottom of spool50 through openings or ports in the bottom of sleeve 41 to channel 70 inspool 50, groove 49 in sleeve 41 and conduit 69 to the top of cylinder37 and piston 38.

When the valve spool 50 is moved downwardly, as above described, to theposition shown in Fig. 5, bydraulic liquid flowing from the high volumeoutput port of pump 28 in conduit 64 travels through conduit 68 togroove 47 in sleeve 41 and from it through a check valve 72 and conduit71 to the bottom of spool 50 where it combines or merges with the outputfrom the low volume output port of pump 28 and flows through thepassages described to the top of the cylinder 37 and piston 38. Thisliquid, of course, will move the piston 38 downwardly and the liquidbelow the piston 38 will be expelled through conduit 64 and be combinedor merged with the fluid entering the conduit 64 from the high volumeoutput port of pump 28. It will thus be seen that the piston 38, whichis an unbalanced piston, will be moved downwardly rapidly since thecombined output volumes of both of the output ports of pump 28 and theoutput from the bottom of cylinder 37 are merged and supplied to the topof the piston 38.

It should be noted that once the spool 50 has been moved to the positionshown in Fig. 5 that valve 61 may be opened since the output line 66thereof is closed by the isolation of groove 46 from the interior ofsleeve 41 by a land on the spool 50. In other words, there is presenttwo valves connected in series and either may function to block the flowof liquid from the groove 45 and the upper end of valve spool 50. Itshould also be noted that the maximum pressure in the top of cylinder 37is controlled by an adjustable relief valve 73.

The ram 32 will travel freely toward the press bed 23 at a fasttraverse" speed until the ram 32 engages work on the bed, for example,after which, of course, very little liquid will be displaced from thebottom of cylinder 37. The resistance oifer ed to the m'evenieatof 32upon engaging work on the bed 23 Will cause the pressure in the cylinder37 to increase and this increase in pressure will be reflected to thetop of valve spool '50 to cause the unloading piston 55 to move upwardlyto compress spring 60 and rest upon a shoulder or stop in the bore 44 incap 39.

As the unloading piston 55 moves upwardly, thelost motion connectionprovided by the slot 57 in extension 56 and pin 58 lifts the valve spool50 to the position shown in Fig. 6 of the drawings, and when the partsof the control unit 21 are in the position shown in said Fig. 6 only thepressure supplied from the low volume output port of pump 28 throughconduit '63 'is 'applied to the top of the piston 38. For this reason,substantially all of the energy of motor 22 is employed to drive pump 28against the pressure of its low volume output port in conduit 63.

Upon the movement of valve spool St) to the position shown in Fig. 6,all of the high volume output of pump 28 flowing in line 64 as well asthe chamber formed in the bottom of cylinder 37 below piston 38 isconnected to tank 26 through the conduit 63, groove 47 in sleeve 41, agroove 74 in spool 59, groove 48 in sleeve 41 and drain conduit 34. Atthis time all of the low volume pump output flowing in conduit 63 isdirected to the top of piston 38 through the channel or groove 45, thecenter of spool 50 to the chamber at the bottom thereof and throughgrooves 759 and 49 to conduit 69 which leads to the cylinder 37 at thetop of piston 38. At this time the entire top area of said piston iseffective to do work because the smaller bottom area thereof is exposedto tank pressure as described above. I

The maximum pressure that can build up in the'cylinder 37 above piston38 is controlled by the adjustable relief valve 73. When the ram 32encounters a resistance in its movement toward the press bed 23sufiicient to cause valve 73 to open, the ram movement stops and thefull flow of liquid from the low volume output port of pump 28 flowingin conduit 63 is directed through groove 45, line 65, valve 61, conduit66, groove 46 to relief valve 73 and drain conduit 34 to tank 26.Becasue the motion of ram 32 has stopped, there will be substantial lyno flow of liquid through the orifices 51 and 53 and the spool 50 willbe returned to the positoin shown in Fig. 4 of the drawings by thespring 54 whereby the ram 32 will be moved at a rapid rate of speed toits up position and the parts of the control unit 21 will be placed inreadiness for the next cycle of operation of the press ram.

As previously set forth, the pump 28 delivers two output volumes and asstated, in one embodiment of the invention these output volumes are oneand two gallons per minute. It has been found in practice, however, thatas the output pressures of the pump increase the output volumes willdecrease due to inefficiencies of the pump and leakages of fluidtherein. Because of this fact, the poppet 52 including the orifice 53 isprovided in spool 59. The orifice 53 in poppet 52 is of less diameterthan the orifice 51 in the partition in spool 50 and when the outputpressure of the low volume output port of pump 28 is low and valve 61 isfirst closed, as described in connection with Fig. 4, the volume andpressure of liquid flowing to the top of valve spool 54 is such that itwill pass through the orifice 51 and lift the poppet 52 off of its seatwhile moving the piston 50 downwardly without lifting the unloadingpiston 55. As the volume of liquid pumped to the top of piston 50decreases due to increased pressure, the poppet 52 which is being urgedto its closed position by spring 54 causes orifice 53 to becomeeffective to restrict the flow of liquid and thereby provide thenecessary pressure differential between the opposite ends of spool 50 tohold it in the position seen in Fig. 5. It will thus be seen that thepoppet 52 and orifices 51 and 53 cooperate to provide an assemblyineluding variable orifice means which is responsive-re pre vide thenecessary pressure differential 'at'opposite ends of the spool 50 eventhough both the pressure andv'olume of liquid supplied to the top ofsp'o'olmay vary. I

It is pointed out that if the valve 61 is held in its closed positionthat the automatic reversal feature of the apparatus which occurs whenvalve 73 opens will be prevented from becoming operative until the valve61 is permitted to open. Thus, a press operator by keeping the solenoid62 energized may cause the ram 2% to dwell upon the work. When the valve61 is held closed the low volume output of pump 28 flows through conduit63, the groove 45, the center of spool 55) to the chamber at the bottomthereof, the conduit 71, check valve 76, conduit 66, groove 46, reliefvalve 73- and conduit 34 to tank26.

From the foregoing description, it will be seen that the inventionprovides a control unit 21 which may be employed with facility, forexample, in a hydraulic press to cause the press to idle with its-ramheld in a retracted position and that to initiate acycl'e'o'f operationof the rain it is necessary only to close the valve 61 momentarily, oruntil the valve spool 50 shifts from the position seen in Fig. 4 to theposition'seen in Fig. 5 of the drawings and that thereafter a cycle ofoperation, namely a rapid approach of the ram to the Work, a buildup ofram pressure to the setting of valve 73, and a rapid return of the ramto its up or press idling position will be completed automatically.

It will also be obvious that when the'ram is travelling toward the workthat both volumes of liquid pumped by the pump and liquid displaced frombelow the piston 38 are merged and supplied to the top of cylinder 37 toforce the piston 33 downwardly at ahigh rate of speed and that when inits downward movement the re-r1132 meets sufficient resistance toincrease the hydraulic pres sure above the piston 38 and spool Sit tolift the unloading piston 55 and spool 50, that only the smaller outputvolume of pump 23 flowing in conduit 63 is applied to the top of piston38 and the higher output volume of pump 28 flowing in conduit 64 and thebottom of the motor cylinder 37 are connected to exhaust.

This condition will continue to exist until the hydraulic pressure abovethe piston 38 increases and opens valve 73 at which time the spring 54will return spool 59 to the position seen in Fig. 4 of the drawingswherein both volumes of hydraulic liquid being pumped by pump 28 will bemerged and supplied to the bottom of piston 38 to elevate or retract theram 32 at a high rate of speed.

While the form of embodiment of the present invention as hereindisclosed constitutes a preferred form, it is to be understood thatother forms might be adopted, all coming within the scope of the claimswhich follow.

I claim:

1. In a hydraulic press, a hydraulic ram operating mo tor including acylinder, a ram operating piston in said cylinder having opposite facesof unequal areas whereby equal hydraulic pressures applied to said facescauses said piston to move from a first position in said cylinder, meansfor directing liquid to said motor to cause movement of said piston inopposite directions, said means including means for delivering twoseparate volumes of liquid, pressure differential operated valve meansfor first directing both of said volumes of liquid to said motor therebyurging said piston to said first position, means operative to create apressure differential for operating said valve means whereby the latterdirects both of said volumes to said motor to cause the piston thereofto move toward a second position, means for merging liquid displacedfrom said motor by movement of said piston with said two volumes whilesaid piston is moving from said first to said second position, and meansresponsive to an increase in pressure in said motor after said pistonhas moved from said first position to cause said valve means to directone of said volumes to said moeam 7 tor and the other to exhaust,v saidvalve means being responsive to a decrease in said pressure differentialfor re-directing both of said volumes to said motor to return saidpiston to said first position. 1

a 2. In a hydraulic press, a hydraulic ram operating motor including acylinder, a ram operating piston in said cylinder, means for directingliquid to said motor to cause movement of said piston in oppositedirections said means including means for delivering two separatevolumes of liquid, pressure differential operated valve means for firstdirecting both of said volumes of liquid to said motor thereby urgingsaid piston to a first position, means operative to create a pressuredifierential for operating said valve means whereby the latter directsboth of said volumes to said motor to urge the piston thereof to movetoward a second position, and means responsive to an increase inpressure in said motor after said valve means has operated as aforesaidto cause said valve means to direct one of said volumes to said motorand the other to exhaust, and means acting upon a decrease in saidpressure differential for causing said valve means again to direct bothof said volumes to said motor to return said piston to said firstposition.

3. In a hydraulic press, a hydraulic ram operating motor including acylinder, a ram operating piston in said cylinder having opposite facesof unequal areas whereby equal hydraulic pressures applied to said facescauses said piston to move from a first position in said cylinder, meansfor directing liquid to said motor to cause movement of said piston inopposite directions said means including means for delivering twoseparate volumes of liquid, valve means for first directing both of saidvolumes of liquid to said motor thereby urging said piston to said firstposition, means for operating said valve means whereby the latterdirects both of said volumes to said motor to cause the piston thereofto move towardta second position, means for merging liquid displacedfrom said 'motor by movement of said piston with said two volumes, meansresponsive to an increase in pressure in said motor when said pistonmoves to said second position to cause said valve means to direct one ofsaid volumes to said motor and the other to exhaust, and meansresponsive to a decrease in the flow of fluid to said motor for causingsaid valve means again to direct both of said volumes to said motor toreturn said piston to said first position.

4. In a hydraulic press, a hydraulic ram operating motor including acylinder, a ram operating piston in said cylinder, means for directingliquid to said motor to cause movement of said piston in oppositedirections said means including means for delivering two separatevolumes of liquid, valve means for first directing both of said volumesof liquid to said motor thereby urging said piston to a first position,means for operating said valve means whereby the latter directs both ofsaid volumes to said motor to cause the piston thereof to move toward asecond position, means responsive to an increase in pressure insaid-motor when said piston moves to said second position to cause saidvalve means to direct one of said volumes to said motor and the other toexhaust, and means responsive to a decrease in the flow of fluid to saidmotor for causing said valve means again to direct both of said volumesto said motor to return said piston to said first position.

References Cited in the file of this patent UNITED STATES PATENTS1,982,711 Vickers Dec. 4, 1934 2,518,782 Hipp Aug. 15, 1950 2,550,723,Ross May 1, 1951 2,672,884 Cross Mar. 23, 1954 2,705,020 Frantz Mar. 29,1955

